Pickup support apparatus for phonographs



May 8, 1951 c. METCALFE ETAL 2,552,199

PICKUP SUPPORT APPARATUS FOR PHONOGRAPHS Filed Oct. 50, 1946 0340787025(2)7022? A amZ/e l A/ammarfimarfle rra/ewiy Patented May 8, 1951 PICKUPSUPPORT APPARATUS FOR PHONOGRAPHS Clifford Metcalfe, Ruislip, andAlexander James Rae, Southall, England, assignors to Electric & MusicalIndustries Limited, Hayes, Middlesex, England, a company of GreatBritain Application October 30, 1946, Serial No. 706,611

In Great Britain October 31, 1945 This invention relates to apparatusfor playing phonograph records in which the pickup arm or tone arm isautomatically applied to a record.

In apparatus of this type the pickup arm or tone arm, hereinafterreferred to as the pickup arm, is fed to a position adjacent the recordso that when lowered the needle engages the smooth outer edge of therecord and some form of mechanism is usually provided for feeding thepickup arm inwardly so that the needle engages the first groove of therecord.

The object of the present invention is to provide an improved andsimplified form of mechanism for causing the needle to engage the firstgroove of the record.

According to the invention there is provided mechanism for feeding thepickup arm to cause the needle to engage the first groove of the recordwhich comprises a first member carried by an angularly movable postsupporting the pickup arm, said member being adapted to be engaged atappropriate times after the needle is in contact with the record by asecond memher which wipes past said first member to cause the needle toengage a groove in the record, one of said members being a leaf springadapted to yield when said groove is reached so that further feedingmovement of said needle is prevented.

In order that the said invention may be clearly understood and readilycarried into efifect the same will now be more fully described withreference to the accompanying drawing, in which:

Figure l is a view in part sectional elevation of part of a pickup armoperating mechanism, and

Figure 2 is a detail view looking in the direction of the arrow inFigure 1.

The invention is shown as applied by way of example to the pickup armsupport of automatic phonograph mechanisms. The pickup arm (not shown)is mounted in a support I carried by an angularly movable post 2, therebeing provided a rod 3 passing through said post 2 and actuated by aface cam 4 mounted for rotational movement beneath said rod 3 and in aplane normal to said post 2, said rod 3 under the action of said facecam 4 being raised and lowered so as to cause the pickup to be raisedand lowered from the record at appropriate times. Said post 2 is alsoarranged to be angularly 2 Claims. (01. 274-13) moved under the actionof a roller 5 mounted cam 4 is carried by a gear wheel 8 which isarranged to be operated at appropriate times so that when the pickupreaches the end of the playing period and after the pickup has beenlifted from the record said post 2 is angularly moved so as to swing thepickup arm outwardly and after a fresh record has been fed to theturntable the sequence of operations is such that the pickup is againswung inwardly and when said rod 3 is lowered under the action of saidface cam 4 the pickup arm is lowered so as to cause the needle to landon the smooth edge of the record. In order to feed the needle into thefirst playing groove of the record a leaf spring 9 is secured to thelower end of said post 2 and said gear wheel 8 is provided with abracket i0 which supports an eccentrically mounted disc Ii which duringrotational move-'- ment of said gear wheel 8, is adapted to wipe pastsaid leaf spring after the needle is in engagement with the smooth edgeof the record, said disc H, due to its frictional engagement with saidleaf spring 9 causing the pickup arm to be fed inwardly until a groovein the record is reached when the spring 9 yields so that furtherfeeding movement of the needle into the record grooves is prevented.Said leaf spring 9 is preferably of bowed form in longitudinal sectionwith the apex of the bowed portion presented to said disc II. The discII is eccentrically mounted so as to be capable of adjustment wherebythe frictional engagement of said disc with said leaf spring can beadjusted, and for this purpose the disc is carried by avertically-extending arm of the aforesaid bracket If] so that theperiphery of the disc H is presented to the apex of said leaf spring andmay be supported on said arm by a captive nut l2 carried by said arm andby a screw 13 which passes through said disc H and into engagement withsaid captive nut 12. The disc II is eccentrically disposed with respectto said screw l3 so that when the screw is loosened the disc can berotated for adjustment purposes.

Although the invention has been described with particularity, it is tobe understood that the particular details and arrangements shown are byway of illustration only and not by way of limitation. Variousmodifications will suggest themselves to those skilled in the art, andare to be considered as falling within the spirit of the invention.

We claim:

1. Pickup support apparatus for phonographs comprising, in combination,a post adapted to support a pickup arm, a support for said post, saidpost being mounted in said support so as to permit oscillating movementof said post about its axis, a rotary cam adjacent said post, saidrotary cam being provided with a cam track, a cam follower mounted onsaid post and coacting with said cam track to produce oscillatorymovement of said post, said cam track being arranged to cause said postto rotate about its axis in one direction through a predetermined angleand to then reverse its direction of rotation through a predeterminedsmaller angle and then release said cam follower from engagement withsaid cam track, an auxiliary cam mounted in fixed relationship to saidrotary cam and arranged for rotary movement therewith, a resilientmember mounted on said post and arranged to be irictionally engaged bysaid auxiliary cam, the position of said auxiliary cam relative to saidrotary cam being such that said frictional engagement occurs only whensaid cam follower is unengaged with said cam track, the relativepositions of said resilient member and said auxiliary cam being suchthat after engagement therebetween further rotation 4 of said auxiliarycam tends to cause continued rotation of said post in said reversedirection, and means for adjusting the degree of frictional engagementbetween said resilient member and said auxiliary cam.

2. Pickup support apparatus in accordance with claim 1 in which themeans for adjusting the frictional engagement between said resilientmember and said auxiliary cam comprises an eccentric mounting for saidauxiliary cam whereby the distance between the resilient member and theauxiliary cam surface is variable.

CLIFFORD METC'ALFE. ALEXANDER JAMES RAE.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 2,289,357 Green July 14, 19422,366,358 Knox et al. Jan. 9, 1945 2,424,132 Alexandersson July 15, 1947

